Rollback is a component of the MediaWiki software that runs Wikipedia. It allows the last user's edits to a given page to be undone with a single mouse click. On Wikipedia, rollback is used to undo problematic edits such as vandalism.

A user who has rollback rights sees a rollback button next to relevant revisions on their watchlist, in page histories and in certain other places. A single click on this button reverses the edit in question, as well any other consecutive preceding edits made by the same user.

Rollback is available to all administrators and can be given to other users on request. Currently, 2 administrators and 2 other users have rollback.

Standard rollback is a fast way of undoing problematic edits, but it has the disadvantage that only a generic edit summary is generated, with no explanation of the reason for the change. For this reason, it is considered inappropriate to use it in situations where an explanatory edit summary would normally be expected. Rollback may be used:

To revert obvious vandalism and other edits where the reason for reverting is absolutely clear

To revert edits that you have made (for example, edits that you accidentally made)

To revert edits by banned users who are not allowed to edit (but be prepared to explain this use of rollback when asked to)

To revert widespread edits (by a misguided editor or malfunctioning bot) which are judged to be unhelpful to the encyclopedia, provided that an explanation is supplied in an appropriate location, such as at the relevant talk page[1]

Use of standard rollback for any other purposes – such as reverting good-faith changes which you happen to disagree with – is likely to be considered misuse of the tool. When in doubt, use another method of reversion and supply an edit summary to explain your reasoning.

The above restrictions apply to standard rollback, using the generic edit summary. If a tool or manual method is used to add an appropriate explanatory edit summary (as described in the Additional tools section below), then rollback may be freely used as with any other method of reverting.

As with other methods of reverting, when using rollback to restore text to a page, ensure that the text restored does not violate Wikipedia policies.

Administrators may revoke the rollback feature or issue a block in response to a persistent failure to explain reverts, regardless of the means used. However, they should allow the editor an opportunity to explain their use of rollback before taking any action – there may be justification of which the administrator is not aware (such as reversion of a banned user). Similarly, editors who edit war may lose the privilege regardless of the means used to edit war. Administrators who persistently misuse rollback may have their administrator access revoked.

While there is no fixed requirement, a request is unlikely to be successful without a contribution history that demonstrates an ability to distinguish well-intentioned edits with minor issues from unconstructive vandalism.

If you have been granted rollback and are not sure how it works, you may wish to test it out here.

It is also possible to use rollback with an explanatory edit summary (instead of the default or standard generic edit summary). Various editing tools let you do this; for example, see this list of tools. To do it manually, copy the URL of the rollback link, paste it into your browser's address bar, and append &summary= followed by your desired summary to the end of the URL.

The patrolling tool Twinkle adds links in similar places to the "rollback" links, and also calls them "rollback". Anyone using both will see both types of "rollback" link, which can be a little confusing. Unlike rollback, Twinkle may be used by anyone. Other than this, the links are functionally the same, but differ in their choice of edit summaries. Twinkle also offers additional options.